This patent application claims priority of Japanese Patent Application No. 11-267393, filed Sep. 21, 1999 and of Japanese Patent Application No. 2000-285328, filed Sep. 20, 2000.
1. Field of the Invention
The present invention relates to a macro-cell-creating method, macro-cell-creating apparatus, and the like, and more particularly, to a macro-cell-creating method, comprising a basic logical circuit (hereinafter referred to as a xe2x80x9cbasic function cellxe2x80x9d) such as a NAND gate, flip-flop, inverter, and the like, in an ASIC (Application Specific Integrated Circuit) such as a gate array, standard cell, embedded array, and the like, and the macro-cell-creating apparatus and the like.
2. Description of the Related Art
Recently, an ASIC which realizes an IC (Integrated Circuit) for a specific application is actively developed. The ASIC is composed of a combination of a plurality of macro cells, each thereof being a circuit unit having a fixed function. The macro cell is composed of a combination of a plurality of basic function cells, each thereof being a basic element of a logical circuit. In recent years, with propagation of the ASIC, a circuit scale of the ASIC is rapidly increased, and a circuit scale of the macro cell, comprising the ASIC, is also increased.
On the other hand, the ASIC is required to be developed more efficiently in a shorter time. Accordingly, efficient designing of a macro cell, namely, efficient disposition and wiring of a plurality of basic function cells become important.
FIG. 6 is a flowchart showing a conventional macro-cell-creating method, and FIG. 7 is a schematic plan view showing a macro cell 600 created by the conventional macro-cell-creating method.
The macro cell 600 comprises, as shown in FIG. 7, a plurality of basic function cells such as basic function cells 611 to 613, 621 to 623, 631 to 633, and the like, and the basic function cells 611 to 613, 621 to 623, and 631 to 633 are provided with input/output terminals 641 to 649 of the macro cell 600, respectively. Furthermore, from the input/output terminals 641 to 649 of the macro cell 600, wiring lines 651 to 659 are provided for drawing out the input/output terminals 641 to 649 thereof onto the outside of the macro cell 600, respectively.
Now, a conventional macro-cell-creating method is described. As shown in FIG. 6, firstly, circuit connection information 511 showing connection states among the basic function cells, a size estimate 512 of a circuit of the desired macro cell 600, and input/output terminal information 513 of a circuit of the macro cell 600 are previously prepared, and these are stored in a storage medium or the like (step S500).
Then, based on the size estimate 512 of the circuit of the macro cell 600, a frame of the macro cell 600 is created (step S501).
Then, the circuit connection information 511 about the basic function cells included in the macro cell 600 is consulted, and all basic function cells including the basic function cells 611 to 613, 621 to 623, 631 to 633, and the like are disposed within the frame of the macro cell 600 created in step S501 (step S502).
Then, all of the basic function cells including basic function cells 611 to 613, 621 to 623, 631 to 633, and the like, disposed on the macro cell 600 in step S502, are wired (step S503).
Then, the input/output terminal information 513 of the circuit of the macro cell is consulted, then wiring lines 651 to 659 are wired for drawing out the input/output terminals 641 to 649 of the macro cell 600 created in step S503 to the outside of macro cell 600, and macro cell layout data 514 are created (step S504).
However, according to the conventional macro-cell-creating method as shown in FIG. 6, when basic function cells are disposed on a macro cell, only the circuit connection information about the basic function cells is consulted at the disposition, and accordingly the wiring for drawing out the input/output terminals of the macro cell to the outside of the macro cell becomes more complicated as well as longer, thereby causing a problem that operation speed of the macro cell is lowered.
Further, when creating a macro cell, calculation of the delay values regarding input/output terminals of the macro cell is necessitated, however, according to the conventional macro-cell-creating method, since the input/output terminals of the macro cell are drawn out to the outside of the macro cell by draw-out wiring, the delay values regarding the input/output terminals of the macro cell are to be calculated from the delay values up to the input/output terminals and the delay values of the wiring for drawing out the input/output terminals to the outside of the macro cell. Accordingly, the calculation of the delay values regarding the input/output terminals of the macro cell becomes complicated, thereby causing a problem that the accurate calculation of the delay values is difficult.
Thereupon, in view of the above-described problems, aspects of the present invention can provide a macro-cell-creating method capable of accurately calculating the delay values regarding the input/output terminals of the macro cell and capable of efficiently designing a high-speed macro cell, even if a circuit scale of the macro cell is increased.
Further, aspects of the present invention can provide a library of a macro cell layout data, capable of calculating a wiring delay time accompanied to mutual connection of the macro cells on the integrated circuit level, thereby contributing to shortening of designing time and facilitation of the designing, when an integrated circuit is designed by use of a plurality of macro cells.
Furthermore, aspects of the present invention can provide a macro-cell-creating apparatus for realizing the above described aspects.
Moreover, other aspects of the present invention can provide a recording medium which is necessitated when the macro-cell-creating method is realized by a computer.
In order to solve the above-described problems, a macro-cell-creating method is constituted as follows.
That is, the macro-cell-creating method of the present invention is a macro-cell-creating method for creating a desired macro cell based on a plurality of basic function cells respectively provided with a fixed function, and is characterized by comprising a first step for creating a frame of the macro cell based on a size estimate of the desired macro cell, a second step for disposing provisional external input/output terminals for drawing out input/output terminals of the basic function cells onto the frame of the macro cell, based on input/output terminal information of the macro cell circuit, a third step for consulting with connection information between the provisional external input/output terminals and input/output terminals of the basic function cells, in addition to circuit connection information about the basic function cells, to dispose the plurality of basic function cells inside the macro cell, and for wiring between the disposed plurality of basic function cells, and a fourth step for deleting wired lines between said provisional external input/output terminals and the input/output terminals of the basic function cells out of the wired lines.
In this way, in the macro-cell-creating methods described above, provisional external input/output terminals are previously provided on the frame of the macro cell, and the connection information of the provisional external input/output terminals is added to the circuit connection information about the basic function cells. Accordingly, the basic function cells actually having input/output terminals can be disposed at positions close to the provisional external input/output terminals.
Furthermore, in the macro-cell-creating methods described above, draw-out wiring lines connecting the input/output terminals of the basic function cells with the provisional external input/output terminals are deleted. As a result, the delay values of the draw-out wiring lines are no more required to be derived, thereby the delay values regarding the input/output of terminals of the macro cell can be accurately calculated, and further a higher-speed macro cell can be designed.
In the above-described macro-cell-creating method, the size estimate of the macro cell, the input/output terminal information of the macro cell circuit, and the circuit connection information about the basic function cells can also be previously prepared prior to the first step.
In this way, by previously preparing the size estimate of the macro cell, the input/output terminal information of the macro cell circuit, and the circuit connection information about the basic function cells, creation of the frame of the macro cell, disposition of the provisional external input/output terminals, and disposition and wiring of the basic function cells can be efficiently performed.
Further, a library can be provided as follows.
That is, a library of layout data of the macro cell created as described above, and as the layout data, at least the size of the macro cell, and the positions of the input/output terminals of the basic function cells, from which wired lines connected with the provisional external input/output terminals are deleted, are registered, and respective data thereof can be read by a computer.
Thus, when a larger scale integrated circuit is designed by utilizing a plurality of the libraries, a wiring delay time accompanied to mutual connection of the macro cells can be calculated on the integrated circuit level, thus contributing to shortening of the designing time and to facilitation of the designing.
Furthermore, macro-cell-creating apparatuses can be constituted in the following way.
That is, a macro-cell-creating apparatus for creating a desired macro cell based on a plurality of basic function cells respectively provided with a fixed function can be provided, and is characterized by comprising a frame creating means for creating a frame of the macro cell based on a size estimate of the desired macro cell, a provisional terminal disposing means for disposing provisional external input/output terminals for drawing out input/output terminals of the basic function cells onto the frame of the macro cell, based on the input/output terminal information of the macro cell circuit, a connection information adding means for adding the connection information between the provisional external input/output terminals and the input/output terminals of the basic function cells to the circuit connection information about the basic function cells, a disposing/wiring means for disposing the plurality of basic function cells inside the Afro cell based on the added circuit connection information, as well as for wiring between the disposed plurality of basic function cells, and wired line deleting means for deleting wired lines connecting the provisional external input/output terminals with the input/output terminals of the basic function cells out of the wired lines.
The above-described macro-cell-creating apparatus also can further comprise a storage means for previously storing the size estimate of the macro cell, the input/output terminal information of the macro cell circuit, and the circuit connection information about the basic function cells.
As such, the macro-cell-creating apparatus described above is previously provided with the provisional external input/output terminals on the frame of the macro cell, and the connection information of the provisional exterior input/output terminals is added to the circuit connection information about the basic function cells. As a result, the basic function cells actually having the input/output terminals can be disposed at positions close to the provisional external input/output terminals.
Further, in the macro-cell-creating method described above, draw-out wiring lines connecting the input/output terminals of the basic function cells with the provisional external input/output terminals are deleted. As a result, a delay value of the draw-out wiring is no more required to be derived, thereby the delay values regarding the input/output terminals of the macro cell can be accurately calculated, land further a higher-speed macro cell can be designed.
Moreover, a recording medium can be provided as follows.
A recording medium can be provided having recorded therein a program rendering a computer to execute the macro-cell-creating method, and capable of being read by a computer, including a first step for creating a frame of a macro cell based on a size estimate of a desired macro cell, a second step for disposing provisional external input/output terminals for drawing out input/output terminals of the basic function cells onto the macro cell frame based on input/output terminal information of the macro cell circuit, a third step for consulting with connection information between the provisional external input/output terminals and input/output terminals of the basic function cells, in addition to the circuit connection information about the basic function cells, to dispose the plurality of basic function cells inside the macro cell, and for wiring between the disposed plurality of the basic function cells, and a fourth step for deleting wired lines between the provisional external input/output terminals and the input/output terminals of the basic function cells out of the wired lines.
In this way, the recording medium can have, recorded therein, a program rendering a computer to execute the macro-cell-creating method, and can be read by the computer. As a result, the macro-cell-creating method can be realized by utilizing a computer.
Additional features and advantages of the invention will be set forth in the descriptions that follow and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description are. Exemplary and explanatory and are intended to provide further explanation of the invention as claimed.